ODP046 Initial Lessons from a Prescreening Protocol to Identify Participants with Classic CAH Potentially Eligible for Gene Therapy Treatment with BBP-631, an Adeno-associated Virus (AAV) Serotype 5-Based Recombinant Vector Encoding the Human CYP21A2 Gene

 

Here we present the design and early findings from CAH-300 /NCT05101902, a prescreening protocol to identify participants who are potentially eligible for the CAH-301 Phase 1/2 treatment trial with BBP-631, an AAV5-based gene therapy for classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD). The CYP21A2 gene encodes the 21-hydroxylase enzyme that plays a critical role in glucocorticoid and mineralocorticoid synthesis by the adrenal cortex. CYP21A2pathogenic variants cause 21OHD, the most common form of CAH, characterized by variable degrees of adrenal insufficiency and androgen excess. Standard treatment of classic CAH due to 21OHD usually consists of daily replacement doses of glucocorticoid (GC) and mineralocorticoid. However, supraphysiologic GC doses are often required to mitigate the androgen excess and it is difficult to dose exogenous GCs in a manner that provides adequate disease control while avoiding overtreatment. A gene therapy approach offers the potential to restore cortisol and aldosterone production from the adrenal glands in a physiologically regulated manner. To assess potential eligibility for the gene therapy trial CAH-301, participants in the prescreening protocol CAH-300 undergo initial assessments for the presence of exclusionary anti-21OH antibodies and anti-AAV5 antibodies, as well as for characterization of CYP21A2 genotype. After the participant meets initial eligibility criteria, referral to a treatment trial center may be arranged. To address the challenges in recruiting participants with this rare disorder, prescreening assessments are performed at the participant's home allowing for recruitment from broad geographic areas including those without proximity to a tertiary care center. Home assessments have also provided flexibility for participants during the COVID pandemic. Additional assessments during prescreening that further impact eligibility for the gene therapy trial include review of participant medical history and collection of hormonal biomarkers including 17-hydroxyprogestone, androstenedione, cortisol, and ACTH. Preliminary laboratory data show the expected presence of low cortisol (measured by both gas chromatography-mass spectrometry and immunoassay) with concomitant elevated ACTH, confirming the potential to detect meaningful changes in endogenous cortisol production after BBP-631 dosing. In summary, our prescreening approach with home assessments has enabled the efficient identification of participants potentially eligible for the CAH-301 gene therapy trial. Preliminary data have confirmed the presence of low cortisol and thus potential for detecting meaningful increases in endogenous cortisol production after gene therapy with BBP-631.

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Subcutaneous dosing regimens of tocilizumab in children with systemic or polyarticular juvenile idiopathic arthritis

Objectives

To determine s.c. tocilizumab (s.c.-TCZ) dosing regimens for systemic JIA (sJIA) and polyarticular JIA (pJIA).

Methods

In two 52-week phase 1 b trials, s.c.-TCZ (162 mg/dose) was administered to sJIA patients every week or every 2 weeks (every 10 days before interim analysis) and to pJIA patients every 2 weeks or every 3 weeks with body weight ≥30 kg or <30 kg, respectively. Primary end points were pharmacokinetics, pharmacodynamics and safety; efficacy was exploratory. Comparisons were made to data from phase 3 trials with i.v. tocilizumab (i.v.-TCZ) in sJIA and pJIA.

Results

Study participants were 51 sJIA patients and 52 pJIA patients aged 1–17 years who received s.c.-TCZ. Steady-state minimum TCZ concentration (C_trough) >5th percentile of that achieved with i.v.-TCZ was achieved by 49 (96%) sJIA and 52 (100%) pJIA patients. In both populations, pharmacodynamic markers of disease were similar between body weight groups. Improvements in Juvenile Arthritis DAS-71 were comparable between s.c.-TCZ and i.v.-TCZ. By week 52, 53% of sJIA patients and 31% of pJIA patients achieved clinical remission on treatment. Safety was consistent with that of i.v.-TCZ except for injection site reactions, reported by 41.2% and 28.8% of sJIA and pJIA patients, respectively. Infections were reported in 78.4% and 69.2% of patients, respectively. Two sJIA patients died; both deaths were considered to be related to TCZ.

Conclusion

s.c.-TCZ provides exposure and risk/benefit profiles similar to those of i.v.-TCZ. S.c. administration provides an alternative administration route that is more convenient for patients and caregivers and that has potential for in-home use.

Trial registration

ClinicalTrials.gov, http://clinicaltrials.gov, NCT01904292 and NCT01904279

Functional and fibrinogen receptor studies in platelets in pre-eclamptic toxaemia of pregnancy

It is believed that platelets play a key role in the production of pre-eclamptic toxaemia and toxaemia of pregnancy. Toxaemia of pregnancy is described as a condition of chronic DIC where there is thrombocytopenia as well as raised fibrin degradation products. Since fibrinogen receptors are involved in the final stage of the platelet aggregation reaction, we wanted to investigate the platelet receptors for fibrinogen in normal and abnormal pregnancy. Thirty-six normal pregnant women (12 in their 2nd trimester, 24 in their 3rd trimester), 24 pregnant pre-eclamptic toxaemia cases and 16 non-pregnant controls were included in the present study. All patients with pre-eclamptic toxaemia had oedema, proteinuria and hypertension. Flow cytometric study of platelets was undertaken utilizing fluorescein isothiocyanate (FITC)-labelled anti-human fibrinogen antibody in unstimulated and ADP-stimulated (final concentration 0.02 M) platelets. The intensity of platelet fluorescence was classified into three groups and expressed in arbitrary units. The results indicate that there are a higher number of stimulated platelets expressing fibrinogen receptors in the circulation of patients with pre-eclampsia. Thus, it is possible to hypothesize that platelets showing increased fibrinogen receptors aggregate and form microthrombi in smaller vessels in women with pre-eclamptic toxaemia.

Human umbilical cord blood serum can replace fetal bovine serum in the culture of mesenchymal stem cells

The potential of mesenchymal stem cells (MSC) to differentiate into different cell types has opened up the possibility of using these cells clinically to treat a variety of disorders. In this study we describe the use of human umbilical cord blood serum (CBS) as a replacement for fetal bovine serum (FBS) for culturing MSC from different sources. MSC from human and swine bone marrow and human umbilical cord blood were cultured in the presence of DMEM/F12 containing either FBS or CBS. Human MSC cultured in presence of FBS or CBS showed typical fibroblast-like morphology, which is characteristic of MSC. 99% of the cells cultured in FBS had a CD73+/CD105+/CD45- phenotype compared to 96% of cells cultured in CBS. Cells cultured in CBS had a significantly higher cell count as compared to cells cultured in FBS. Swine Bone Marrow MSC cultured in the presence of FBS and CBS were morphologically and phenotypically similar. Human umbilical cord blood serum supports the growth of MSC. While no significant differences were observed in the MSC numbers in swine cells cultured in the presence of FBS or CBS, human cells showed a greater proliferation potential in the presence of CBS as compared to FBS. Therefore, CBS can be used as an effective substitute to FBS for developing clinically useful protocols for culturing MSC.

Deep Brain Stimulation for Parkinson’s Disease: Association between Stimulation Parameters and Cognitive Performance

Chronic subthalamic nucleus stimulation produces inconsistent patterns of cognitive change in Parkinson's disease patients. Individually tailored stimulation parameters may contribute to this variable pattern of change. Systematic variation of amplitude, pulse width, and rate of stimulation has been reported to produce unique changes in motor and limbic response. To evaluate the association between stimulation parameters and cognitive/behavioral response, neuropsychological performance and stimulation parameter data of 8 Parkinson's disease patients were submitted to Pearson r correlation analysis. Results indicate that each stimulation parameter was significantly associated with a subset of measures. The current findings raise the possibility that adverse cognitive/behavioral responses may be treated through parameter modification while maintaining motor symptom efficacy.

Acquired immunodeficiency syndrome and health care professionals

As health care professionals, we face a grave risk of acquiring HIV infection in the course of our work. But how many of us really know the precautions to be applied in the hospital set up in dealing with HIV infected patients? A knowledge, attitude and practice (KAP) study was conducted in Pune hospitals to assess the current status. Among the results 65% servants had not heard of AIDS, 85% nursing staff did not apply the Universal Safety Precautions (USP) approach, 13.5% resident thought that the HIV was not transmitted by blood, 30% consultants would avoid contact with an HIV positive patient. This study has shown that definite lacunae exist in knowledge specific to the particular population in question. A proposal for an education programme which is target specific and one of constant renewal is sought.